Injector-pump mechanism



Feb. 11, 1930. F. CARTER El AL.

INJECTOR PUMP MECHANISM Filed May 13, 1929 U W n/ram KM/F/YAZ A? CAfi/Z/F 147T ORNE Y Patented Feb. 11, 1930 UNITED STATES PATENT ornca rm: oan'rnn m nvmsnlm enamors'rmonn, momma, .assreaone or onn-rnmn 'ro ononanmns nmcxsronn, or srmonn, ENGLAND lumen-run uncmmrsu' Application filed lay 18, 1989, lo. 868, and in Great Britain ll'ovember I8, 1888.

This invention relates to mechanism for actuating reciprocating plunger fuel pumps for internal combustion engines of the kind in which liquid fuel without an admixture of air is injected into the dombustion chamber at a predetermined fixed point in the cycle,

the end of the injection period being adjusted automatically by means of a governor.

The object of our invention is to provide a simple and efiicient governor-controlled mechanism by means of which the pump plunger is disconnected from its driving mechanism when 'a trip operates.

It is a further object of the invention to provide a fuel injector pump-actuating mechanism includinglan actuating member formed in two parts aving hit and miss surfaces so that the effective length of said member may be varied by rotating one of said parts relatively to the other.

It is a further object of the invention to rovide a pump-actuating mechanism havmg a drivin and driven member enga ing by means of it and miss surfaces, one o the members being rotated at each cycle, whereby the raised parts of the surfaces which engage at the beginning of the fuel-actuating stroke are caused to mlss each other at a point of time in the cycle, which is automatically controlled from the governor.

With this and other objects in view the invention will now be described with reference to the accompanying drawings which illustrate one preferred embodiment, it being understood that suitable equivalents and substitutions may be effected without departing from the spirit of the invention as set forth in the sub'oined claimsl In the rawings, Figure 1 illustrates a sectional view of the actuating mechanism,

Figure 2 being a view of a detail, and

Fi ure 3 showing diagrammatical connection etween the actuating mechanism and the governor.

Turning now to the form illustrated a is a cylindrical casing carried in any suitable position on the engine and b is ahollow reciprocating plunger'actuated by the cam c on the layshaft a driven by the engine. b b are flats formed on the plunger 6 to prevent it shortened.

I the plunger 6 in contact with the cam a, and

turning in the casing, and b b are dog clutch teeth on the inner end of the plunger 6. d. d are similar clutch teeth formed on a hollow plunger, (Z which also carries a pair of op ositely-arranged end way cams 11, one on fy of which is shown, engaging the cams e ormed on a turnably mounted bush 0.

In the operation of the mechanism, b is a driving and d a driven member, and it will be seen that these two parts are adapted to engage by the hit and miss surfaces formed by the raised end faces of the square teeth 6 d. In the position illustrated,the teeth-b d are in operative engagement, but it will be appreciated that if the upper plunger (1 is rotated the teeth of each of the parts be adapted to lie between the teeth of the o posite part so that the effective length of t e driving and driven members 6, d will be In the specification, it is to be understood that the term hit and miss surfaces is not limited to the provision of a plurality of square-ended dog clutch teeth as any equivalent construction of cam-shaped faces may 7 be employed. v

e is a groove cut in the bush e, which is engaged b a grub screw (2 passed through the wall 0 -casing a to prevent the bush from having any endwise movement.

c is a lever the annular position of which 1s regulated by the governor, Figure 3, through the rod f.

d d are look nuts to limit the inward travel of the plunger 4 and g is a springreturned push rod to actuatethe fuel pump, which may rest in a tubular recess g in the end of plunger d.

his a spiral spring in compression to keep also in torsion to hold the cams d in engage- I ment with the cam surfaces 6 the ends of the spring-being bent inwards as at 71. Figure 2, and inserted into transverse holes in the heads of screws. h with left hand threads so that the torsion of the spring screws them up to their heads, one screw it being in the bottom of the recess of plunger 1) and the other in the bottom of the recess of plunger (1.

The operation of the parts illustrated, is as follows 2- Assuming the pump to be full of oil and injection about to take place, the cam c raises the plunger 6 with the raised parts of the hit and miss surfaces b d in engagement. The plunger (1 is therefore lifted by the cam c and thereby the spring-controlrod g which operates the plunger. During the lift of the plunger (1 however, owing to the engagement of the end way. cams d e, the plunger d is rotated during its lift until the end surfaces of the parts d 6 clear each other, whereupon the teeth al fall into the recesses between the teeth 6 and vice versa, thus shortening the effective length of the combined plungers b, d, and terminating the injection stroke, although the bottom face of plunger 6 is still on a raised portionof the cam c. The amount of rotation of the plunger d relatively to its lift is determined by the cams d a, but the point at which such rotation commences and therefore the duration of time which elapses before the hit and miss surfaces clear each other, is determined by the setting of the cam e which as explained, is solid with the arm e which in its turn is rotated by the rod .f according to the adjustment at the time of the governor.

It will, therefore, be appreciated that the duration of the operative stroke of the combined plungers b, d is positively controlled by the setting of the governor.

When the hit and miss surfaces clear each other, the rod 9 forces down the plunger cl until the lower lock nut d engages with the collar d which sits on the boss of lever 6* which in its turn is held up by the end flange of easing a. Plunger 6 remains in the raised position until the cam 0 allows it to fall under the expanding action of spring 71.. When the plunger 1; has reached its lower position, the torsional action of spring h thereupon rotates plunger d to the left in Figurel, until the cam d is again in engagement with the cam e ready for the next stroke.

The spring that returns the rod 9 is of course stronger than the spring h, and if desired it may be utilized also to actuate the fuel pump plunger on the suction stroke.

We claim 1. Fuel injector pump-actuating mechanism including an actuating member formed in two parts having hit and miss surfaces so that the effective length of said member may be varied by rotating one of said parts relativelyto the other.

2. Fuel injector. pump-actuating mechanism including a driving and a driven member engaging by means of hit and miss surfaces, th members being slidable, and one of said members being rotatable.

3. In an internal combustion engine, a overnor, a fuel injecting mechanism inclu 'ng each stroke and means controlled by the governor for determining the amount of rotation of said member.

5. In an internal combustion engine, a governor, a fuel pump, a cam shaft, a slidable element driven by said cam shaft, a slidable element coupled to said pump, said elements engaging by hit and miss surfaces and one of said'elements being capable also of rotation,

the raised parts of said surfaces engaging on the commencement of the lift of the cam, but means being provided whereby lift of said rotatable element causes it to rotate so that the raised surfaces miss after a predetermined travel, the amount of said travel being controlled by the said governor.

6. In an internal combustion engine, a governor, a fuel pump, a cam shaft, 2. slidable element driven by said cam shaft, a slidable element coupled to said pump, said elements engaging by hit and miss surfaces and one of said elements being capable also of rotation, said element carrying a cam-shaped projection, a control member coupled to said governor, said member having a cam surface to engage said cam-shaped projection, whereby during the operation of said member it is rotated to cause the raised portions of said hit and-miss surfaces to clear each other.

7. In a fuel pump actuating means for in A ternal combustion engines, a pair of members engaging by bit and miss surfaces and a single spiral spring tending to urge said members apart and to rotate one of said members so that their raised surfaces are in register.

FRANK CARTER. EVERSHED CARTER. 

